metal roof sheet problem

Member

could anyone help or advise here on problem and solution.
garage roof was done in built up torch on felt when new then staining appeared on deck (garage ceiling) so we laid out a roll off underslate felt then sheeted with metal roof sheets and trims. all done to manufacturers spec but everytime it is dampor wet the same old wet area appearsin garage ceiling, no place else but there though. pulling my hair out trying to get to bottom. can the timber draw dampness as am 100 per cent its not leaking as no drip has ever occured just this wet patch and nothing else. thanks for your time and views greatly appreciated.

Member

thanks for replying its 12degrees fixed by timber fixings which have the washers and caps system. professionals have had a look but nobody can find problem. it has all flashings around it too ther 200 x200 mm just no way can anyone see how water is getting in. could the fixing be drawing dampness? this is puzzling everyone. the fixings dont look over stressed even if they were couldnt see water getting past rubber washer. any advice ideas welcome and appreciated.

Member

its free standing and all timbers can be seen from below. im wondering if the timber fixing with washers might be causing problem, maybe too tight and pressing too hard on rubber washer? just got no idea at all.

AdministratorStaff MemberAdminModerator

its free standing and all timbers can be seen from below. im wondering if the timber fixing with washers might be causing problem, maybe too tight and pressing too hard on rubber washer? just got no idea at all.

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One last time, what kind of slope is on the roof. Is it steep or flat?

Contractor retired

The new felt should have been a good back up for any leaks in the tin. but its not surpising it would show up in the same place, if it is anywhere above the original leak, I would take a closer look at anything on the high side that wasn't changed like fasia, or could the wind be blowing it up the roof under the flashing.

AdministratorStaff MemberAdminModerator

Old dog; I think 12 degree Is about 3/12 pitch
Scot; Is this a shed roof or does it have a peak?

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Well, I saw 12 degrees and thought he was referencing temp. We measure rise and run as 3/12. Oh well, sorry about the confusion, 12 degrees on a roof is not the same as 12 degrees C.

Make sure that the screws are in straight and not crooked or run at an angle. Also make sure any flashings are in tack. If its free standing does the metal extend up past the top edge if so it should have a top flashing that extends down the fascia and down the roof, imagine and inverted L.

AdministratorStaff MemberAdminModerator

All the metal suppliers we have available locally want the metal panels applied to solid decking with a water proofing membrane underlayment. If you place the panels on battens you will compromise the seams when they are walked on. Battens will also cause a damming effect should moisture get behind the panels. An air space will also develop condensation behind the panel.